What is Lithograph Printing?

Lithograph printing is an example of a process that proves frugality is the mother of many inventions. Alois Senefelder of Bavaria had tried his luck at acting without success, but found that his skills as a playwright were faring far better. The cost of printing his plays proved the only obstacle to financial solvency. He determined to learn the process of engraving his own copper plates to reduce his costs. Copper was expensive so he started practicing writing backwards on limestone. He had a mixture of lamp black, liquid wax, soap and rainwater that he used to repair his mistakes on the copper. Whether some of this mixture accidentally spilled on the limestone or Senefelder was practicing with the inky mixture, history doesn’t say. But sometime in 1796 it appears that he discovered that if he wet the stone, ink would adhere anywhere the water was repelled by his waxy ink. He could then press the limestone block against a piece of paper and the image was perfectly reproduced.

Senefelder patented a perfected process in 1799 where a gum Arabic calcium nitrate solution was applied everywhere that an image was not desired. He would wet the plate. Water would stick to the gummed surface. Then ink would be applied. Then the plate transferred the ink to the paper. Because very detailed images were possible, lithography was accepted immediately for the publication of prints.

Senefelder must have found a new calling because he started experiments with multicolor lithography. By 1817 he had designed a press that automated the lithography process. Godefroy Engelmann of France built on Senefelder’s experiments and perfected the process of chromolithography in 1837.

Attempts were made to marry the lithographic process to the rotary press when it emerged, but the limestone plates wore down too quickly to make it cost effective. The advent of photography propelled an interest in reproducing photographs. In 1954 Louis Plambeck,Jr. of DuPont developed the Dycryl polymeric letterpress plate, though French chemist, Alphonse Louis Poitevin is crediting with inventing photolithography in 1855. Wear on the plate continued to be the limiting factor for the widespread use of lithography in publications. Even replacing the limestone with copper plates didn’t resolve the issue.

Then Ira Washington Rubel invented the offset press in 1903. The lithographic offset press took off and with few modifications is still in use today. Almost every magazine you read today is printed on a lithographic offset press. The offset process transfers ink from one cylinder to another rubber covered cylinder. This cylinder then transfers the printed image to the paper. The process is fast and efficient and the plates last through generous print runs.

Lithograph Printing Q&A

Is lithographic printing more cost effective than using in-house laser printers?

Laser printers can only compete on small black and white print jobs. When you move to full color, the laser printer is still costly and slow. If you are looking at a larger print project, lithographic printing wins the price competition.

How good will photographs look using lithographic printing?

Until the advent of personal computers the only way to print a photograph was by using the lithographic process and half-tone screens. It still remains true that the quality of a printed image is directly proportional to the quality of the photograph. If you supply a grainy photograph, lithography won’t improve it. Another factor in printed photo quality is the quality of the paper. A paper with a glossy finish reproduces photographs of better quality.

Conclusion

Lithographic printing will continue to play a major roll in print shops for years to come. Computers assist in the preparation of the copper plates, but the efficiency of this 100 year old technology is still unrivaled.

blog comments powered by Disqus